eo. WrVtaji 33 ;# brr , e eeirp»Jos»»m,»* ,V firs, 0,4 Artki=e le ea rl*" W» 4,» <0» di -411 as • • • • • • • a • • • I a • • I a • 62 '066 INSTITUTE OF TERRESTRI moat 78 CRAIGHALL *-"" EDINBU k, EFI6 4RQ. LAND. INSTITUTE OF TERRESTRIALECOLOGY LIBRARY SERVICE EDINBURGH LABORATORIES BUSH ESTATE, PENICUIK MIDLOTHIAN EH26 OQB THE MANAGEMENT OF SEA BUCKTHORN (HIPPOPHAE RHAMNOIDES L.) ON SELECTED SITES IN GREAT BRITAIN Report of the Hippophae Study Group (The Nature Conservancy) Com osition of the Stud Grou Mr. R. Goodier Chairman Mr. D.G. Hewett Dr. D.S. Ranwell Mr. N.A. Robinson Dr. L.K. Ward Mr. D.A. White Enquiries about this report should be addressed to: Coastal Ecology Research Station, The Nature Conservancy, Colney Lane, Colney, Norwich, Norfolk, NOR 70F. á CONTENTS Preface: D. S. Ranwell Acknowledgements: II Introduction: R. Goodier Chapter 1: The status of Hippophae as part ofthe British Flora Lena K. Ward TI Chapter 2: The ecology of Hippophae within the dune system D. S. Ranwell 1. Chapter3: The fauna of Hippophae Lena K. Ward 12. Chapter4: Hippophae as a management D. S. Ranwell tool and R. Goodier 18. Chapter 5: The control of Hippophae N. A. Robinson 22. Chapter6; Management options for Hippopha8 R. Goodier 28. Chapter7: Results of a survey D. G. Hewett 32. Chapter8: Conclusions and The Hippophae recommendations Study Group 35. Table 1: Hi o hae rhamnoides - recorded ranges.of some soil properties 37. Table 2: Sea buckthorn as used by various species of birds in Ainsdale Sand Dunes National Nature Reserve 38. Table 3: Relative merits of control methods for HippophaU 39. Table 4: Management options for Hippopha8 41. Table 5: Distribution of Hippophae rhamnoides at nationally important sites withdunes 42. Appendix: Management recommendations for individual sites (in tabular form; with a map on which recommended policies are shown in coded form) 46. Bibliography: 50. á PREFACE The sand dune landscape is notable for its.mobility and the variety of plant and animal species it can support. The British coastline contains a remarkable series of dune systems each with a background of species character- istic to most, and each with a distinctive species element dependent on the particular soil and climate type of the region in which it occurs. In addition there is a greater or smaller element of alien species largely dependent for their presence on the intensity of human activity in and adjoining any particular dune system. A national series of sand dune nature reserves has been selected to preserve representative examples of the total sand dune resource and to maintain both the dynamic nature of the landscape and its species variety. Both these special features of dune systems are threatened by current human activities in many ways. This report concerns a dune shrub, sea buckthorn (Hippophaë rhamnoides), which can check sand mobility and reduce species variety, but2 givenwhich time, could be instrumental in paving the way.to new kinds of environmental variety in dune systems. Hippopha* effectively controls the dune environment. It has wide ecological tolerance and wide distribution and is becoming increasingly abundant. It is big enough to suppress most other plant growth on dunes. For thee reasons, it also has potentiality for control of the movements of people in heavily used dune areas as it can form impenetrable barriers. The pollen record suggests that this plant was formerly widespread in Britain on nutrient-rich soils exposed at the end of the last glaciation. With the spread of forests it apparently retreated to the open habitats of the coast. Until recently rabbit grazing held it in check in sand dune habitats. It seems likely that the recent reduction in rabbit populations through myxomatosis, coupled with improved nutrient supply from air pollution, may be indirectly responsible for its present burst of active spread. The success of controlling plant populations depends on clear and realistic aims related to the potentialities of the species concerned and on adequate knowledge of its behaviour. Armed with this we can make rational decisions on whether to allow the establishment of the species or not; plan effective "surgical" eradication at the right stage of invasion; modify the pattern so that grazing or human trampling can help to maintain the pattern we want; or have patience to allow an invasion to run its course and create a new type of community. This repert brings together relevant facts about the biology of Hippopha'6. It attempts to give a balanced assessment of the advantages and disadvantages the species confers in the dune environment, and recommends specific management policies which might be adopted for selected sand dune areas. It is hoped that the information given may also prove helpful to land managers concerned with other sites where Hippophaë occurs or could be introduced. ACKNOWLEDGEMENTS The Hippophae Study Group is greatly indebted to all those who helped to complete survey cards and forms and also, in particular, to Dr. M.C. Pearson (University of Nottingham), Mr. A.E. Smith (Lincolnshire Trust for Nature Conservation), Mr. F.P. Tindall (East Lothian County Council), Mr. T. Dargie (University of Hull), Dr. M.J. Cotton (University of Dundee) and Mrs. J. Whatmough (National Trust, Northern Ireland), who kindly made ” available unpublished information on Hippophae. We are also grateful to Miss Stella Ross-Craig and G. Bell & Sons, Ltd., for allowing reproduction of Fig. 1; to Mr. E.W. Groves (British Museum (Natural History)) for permission to reproduce Fig. 2; to the Botanical Society of the British Isles and Thomas Nelson & Sons, Ltd., for permission to use3; Fig.to Mr G. de Boer (University of Hull) for supplying and allowing us to use the air photo stereograms in Plate 1; and to Mr. A.C. Aldridge, Mrs. A.C. Knowles (nee Blanchard), Mr. J.V. Morley and Mr. R.E. Parker for supplying other photographs used to illustrate the text. Thanks are also due to Miss J.M. Winn and Miss E.J. Reeve for much help in the preparation of the manuscript and to many members of the staff of the Nature Conservancy who helped with advice. INTRODUCTION In the management of natural or semi-natural environments certain species demand particular attention. This may be because they are the natural "dominants" which determine the whole character of the environMents, or because they are rarities which depend on a delicate environmental balance for their survival)or % because they are species which are themselves capable of causing great changes in the environmental 131ance. Invasive alien species are a special case within this last category and have often drawn attention to themselves, as in the case of the grey squirrel or the coypu, by the spectacular biological disturbance they are capable of causing. In the plant kingdom similar disturbances have been and are being caused by the spread of invasive plant species, and are of special concern to persons involved in the conservation management of natural or semi-natural environments, in particular nature reserves, where the selection of the reserve has been related to the conservation of some specified ecological system. In some cases, such as in the explosive spread of the New Zealand willow-herb (E ilobium edunculare) in montane Britain, there is little that can be done except observe the process, because the possibility of changing its course seems remote. In other cases)such as that of the rhododendron (Rhododendron onticum) and sea buckthorn (Hi o hag rhamnoides) there is a need to develop a clear cut national management policy, at least as far as nature reserves are concerned. The highly invasive behaviour of sea buckthorn on certain sand dune systems has, in the past, brought it the reputation of being a pest species on some sand dune National Nature Reserves and stimulated the thought and action which led to the formation of the Hippophag Study Group under the auspices of the Nature Conservancy's Coastal Habitat Team. However, although it is legitimate to regard Hippophad as an invasive pest Species in some circumstances, this is an over-simplified view of the situation on anything more than a local level. The Hippophad Study Group, at its first meeting in December 1969, set itself the following aims :- 1. To collect information relating to the natural history of Hippophad and the plant communities of which it forms part. 2. To collect information on the fauna associated with Hippophad. 3. To collect information on the current use of Hippophad in environmental management. To examine and make recommendations on methods of controlling Hippophad. 5. To examine the alternative policies for the management of Hippopha4 on selected sites. 6. To propose general, national policies for the management of Hippophag and make recommendations on the management policies in relation to Hippopha8 on the whole range of sand dune National Nature Reserves. It must be emphasised that the Study Group did not consider that it should undertake an exhaustive investigation of the problems associated with HippophaU management but rather that it should produce a satisfactory framework for the necessary immediate local action on Hippopha8 management required by Regional Officers of the Nature Conservancy. At the same time an attempt was made to form the basis of a national yet flexible policy. During the preparation of the draft report many interesting issues arose that invited further investigation, but the pursuance of these was judged to be a follow-up function more appropriate for future research workers. Hippophae rhamnoides L. Sea-Buckthorn A, male flowering branches on part of main stem; B, female flowering branches on part of main stem; C, fruiting branch with young leafy shoots; D, male flower, and a bract, showing the inner surface; E, female flower, cut and opened out; F, drupe— partly cut away to show the stone; G, stone—part of the membraneous covering cut away to show the seed; H, seed; I, J, upper and lower surfaces of leaf.